Carburetor



Nov. 28, 1950 o. A. ARVASTSSON 2,531,661

CARBURETOR Filed Nov. 25, 1946 F15. I I3 7a ELECTEICHL sou/m5 Patented Nov. 28, 1950 CARBURETOR Otto Alfred Arvastsson, Malmo, Sweden Application November 25, 1945, Serial No. 712,086 In Sweden August 17, 1940 Section 1, Public Law 690, August 8, 1946 Patent expires August 17, 1960 3 Claims.

My invention relates to improvements in carburetors for internal combustion engines, and it consists in the combination, construction and arrangement hereinafter described and claimed.

An object of my invention is to provide a carburetor permitting efiicient use of relatively heavy fuels or fuels having a relatively high con tent of water.

Another object of the invention is to provide a carburetor of a simple and reliable construction suitable for relatively heavy fuels or fuels having a relatively high content of water.

My improved carburetor is of the type comprising a mixing chamber having a main air inlet and an outlet to be connected to the intake manifold of the engine, a fuel nozzle opening into the mixing chamber, a float chamber with which the fuel nozzle communicates, and a valve which under the control of the float in the float chamber controls the supply of fuel to the float chamber. In carburetors of this type it is already known, for instance from the Swedish Patents Nos. 69,202 and 71,123, to provide a heating chamber fitted with heating elements around the float chamber and to provide this heating chamber with an air inlet from atmosphere and with an air outlet opening into the mixing chamber of the carburetor, so that the heating elements in said heating chamber may be utilized for heating both the fuel in the float chamber and part of the air entering the mixing chamber. One object of my invention is to improve carburetors provided with heating means of this special nature for both the fuel and part of the air. The improvements consist largely in such an arrangement of the air outlet from the heating chamber and the fuel nozzle opening into the mixing chamber that the said outlet for the heated air from, the heating chamber surrounds the :fuel nozzle and serves the purpose of causing the heated air to atomize or vaporize the fuel from the fuel nozzle before theforming mixture of the atomized or vaporized fuel and the heated air are allowed to mix with the rest of the air in the mixing chamber. I have found this arranga ment to result, both in a very simple and reliable construction of the carburetor and in the possibility of using relatively heavy fuels and fuels with a relatively high content of water, for instance motor alcohol with a water content of up to about 20%.

My invention is illustrated in the accompanying drawing, in which Fig. 1 is a vertical section of a carburetor QQQ," structed according to my invention, and

Fig. 2 is a horizontal section substantially on the line II--II in Fig. l.

The drawing is somewhat diagrammatic, parts not necessary for the understanding of the illvention being omitted for the sake of clearness.

As shown on the drawing the carburetor comprises a float chamber 1 and a mixing chamber 2. The mixing chamber 2 is provided with a main air inlet 3 and an outlet 4 which latter is adapted to be connected to the intake manifold of the engine. The air inlet 3 is provided with a choke valve 5, and the outlet =1 is provided with the usual mixture throttle valve 6. The fuel is supplied through a pipe 1 and enters the float chamber I through a valve t under the control of the float 9. Around the float chamber I there is a heating chamber is provided with an air inlet H and fitted with electric heating elements l2 and having an air outlet opening into the mixing chamber 2 as will be described more in detail hereinafter. The heating chamber is can be heated not only by the electric heating elements 12 therein but also by exhaust gases from the internal combustion engine, for which purposes there is provided outside of the heating chamber i8 a chamber or channel [3 which preferably may extend also around the mixing chamber 2 and has an inlet It and an outlet [5 for the exhaust gases. From the float chamber 1 the fuel passes through a passage I6 to a nozzle l1 projecting centrally in the mixing chamber 2 from the bottom thereof. The communication between the nozzle I? and the fuel passage l6 may be adjustable by means of an adjusting valve Ill. The heating chamber H) has an extension l9 extending beyond and embracing the base portion of the nozzle H and having in its top wall an opening fitted with a tubular member 20 concentrically surrounding and preferably projecting somewhat above the nozzle l! in the mixing chamber 2 and forming the outlet into the latter for the air heated in the heating chamber 18.

Obviously part of the air will be sucked into the mixing chamber 2 through the heating chamber ill, and the rest of the air will be drawn in through the main air inlet 3. I prefer to heat the heating chamber 10 by means of the electric heating elements I 2 only before and during starting of the engine when cold, and to facilitate the starting the main air inlet 3 may be choked by means of the choke valve 5. During normal working of the engine the heating of the heating chamber H3 is effected preferably only by passing part of the hot exhaust gases from the engine through the chamber or channel IS, the main part of the air being sucked in through the main air inlet 3. The smaller part of the air sucked in through the heating chamber In is heated therein, and because of the disposition of the heating chamber I around the float chamber I also the fuel therein is heated. On account of the arrangement of the tubular outlet 2!! for the heated air into the mixing chamber 2 the heated air from the heating chamber 10 will pass the nozzle I1 and atomize or vaporize the fuel before the forming mixture of the heated and atomized or vaporized fuel and the heated air are allowed to mix with the rest of the air sucked in through the main air inlet 3. By thus heating the fuel in the float chamber I and part of the air in the surrounding heating chamber :0 and utilizing only this heated relatively small part of the air for effecting atomization or vaporization of the fuel from the fuel nozzle ll before allowing the forming mixture of the heated air and the atomized or vaporized fuel to mix with the main part of the air in the mixing chamber 2 I obtain the advantage of making possible an eificient u e of relatively heavy fuels and fuels with a relativelv great water content in conventional automobile and like engines which otherwise require relatively light fuels. As will be seen from the drawing the carburetor according to the invention is of a very simple construction and, therefore, relatively cheap in manufacture and reliable in action. If desired an additional fuel passage 2| may be branched off from. the fuel passage l5 and open into the u per part of the mixing chamber 2 and be provided with suitable control means as diagrammatically indicat d at 22.

What I claim and desire to secure by Letters Patent is:

l. A carburetor for internal comb stion engines comprising a float chamber, a mixing chamber having a main air inlet and an outlet to be connected to the intake manifold of the engine, said main air inlet being open to the atmosphere and constituting a direct extension of said mixing chamber, a tubular fuel vaporizing chamber vertically arranged in said mixing chamber and opening into said mixing chamber, a fuel nozzle in said tubular fuel vaporizing chamber vertically and concentrically arranged therein and communicating with said float chamber, the upper end of said fuel nozzle being substantially below the upper edge of said tubular vaporizing chamber, a heating chamber surrounding said float chamber and having an air inlet, an extension on said heating chamber constituting a heated air outlet, said heated air outlet opening into the lower end of said tubular fuel vaporizing chamber around said fuel nozzle, and heating means in said heating chamber whereby air enters said heating chamber and upon being heated by said heating means heats said float chamber and fuel therein and subsequently passes into said tubular fuel vaporizing chamber, ejecting heated fuel from said nozzle into said tubular chamber, vaporizlng and further heating the heated "fuel in said chamber, unheated air from said main air inlet passing the open end of said tubular chamber into said mixing chamber and ejecting the heated and vaporized mixture from said tubular fuel vaporizing chamber into said mixing chamber for further mixing with the unheated air from said main air inlet open to the atmosphere before entering the engine through said intake manifold.

2. In a carburetor for internal combustion engines as claimed in claim 1, an auxiliary heating chamber surrounding said heating chamber and said mixing chamber, said auxiliary heating chamber having an inlet and an outlet, said inlet being connected to the exhaust manifold of said engine.

3. A carburetor for internal combustion engines comprising a float chamber, a mixing chamber having a main air inlet and outlet to be connected to the intake manifold of the engine, said main air inlet being open to the atmosphere and constituting a direct extension of said mixing chamber, a tubular fuel vaporizing chamber vertically arranged in said mixing chamber and opening into said mixing chamber, a fuel nozzle having lateral openings in proximity to the top thereof in said tubular fuel vaporizing chamber vertically and concentrically arranged therein and communicating with said float chamber, the lateral openings in said fuel nozzle being below the upper edge of said tubular vaporizing chamber, a heating chamber surrounding said float chamber and having an air inlet, an extension on said heating chamber constituting a heated air outlet, said heated air outlet opening into the lower end of said tubular fuel vaporizing chamber around said fuel nozzle, heating means for said heating chamber whereby air enters said heating chamber and upon being heated by said heating means heats said float chamber and fuel therein and subsequently passes into said tubular fuel vaporizing chamber, ejecting heated fuel from said nozzle into said tubular chamber, vaporizing and further heating the heated fuel in said chamber, unheated air from said main air inlet passing the open end of said tubular chamber into said mixing chamber and ejecting previously heated and vaporized mixture from said tubular vaporizing chamber into said mixing chamber for further mixing with the unheated air from said main air inlet open to the atmosphere before en tering the engine through said intake manifold.

OTTO ALFRED ARVASTSSON.

REFERENCES CITED The following references are of record in the file of this patent;

UNITED STATES PATENTS Number Name Date 1,043,342 Musgrave et al. Nov. 5, 1912 1,263,967 Van Daam Apr. 23, 1918 1,326,000 Schmid Dec. 23, 1919 1,463,034 Bennett July 24, 1923 1,757,920 Ottosson May 6, 1930 1,798,065 Clark Mar. 24, 1931 11,834,766 Briggs Dec.'1, 1931 1,941,862 Heitger Jan. 2, 193 

